1. Field of the Invention
The present invention relates to a stereoscopic image display apparatus, a stereoscopic image display method, and a program that causes a computer to execute a stereoscopic image display method, for displaying stereoscopic images which are generated from a plurality of images.
2. Description of the Related Art
Various methods have been proposed to perform three dimensional display, in which planar images are displayed to be perceived as three dimensional images. In three dimensional display, parallax, which occurs due to the distance between right eyes and left eyes, is intentionally generated to cause three dimensional perception, in which images appear to float out from display surfaces. For example, in three dimensional visual perception according to the naked eye parallel viewing method, two images that each correspond to the right eye and the left eye respectively are prepared, and three dimensional display is realized by shifting the position of a single object within the two images in the horizontal direction to generate a stereoscopic image.
In addition, methods for performing three dimensional display by generating stereoscopic images from a plurality of overlapped images having different colors such as red and blue, and by generating stereoscopic images from a plurality of images which are combined such that the lines thereof are alternately arranged, have also been proposed. In these methods, the stereoscopic images can be viewed three dimensionally, by the eyes stereoscopically viewing the stereoscopic images which are displayed using red/blue glasses or polarizing glasses. It is also possible to display the stereoscopic images on a stereoscopic display monitor, which obviates the use of the polarizing glasses and the like.
Compound lens cameras that have a plurality of imaging sections in order to perform three dimensional display have also been proposed. These compound lens cameras are capable of generating stereoscopic to perform three dimensional display during photography. When camera operations are to be performed during the three dimensional display, it is necessary to display menu screens to input operation commands. However, stereoscopic images are displayed three dimensionally, such that spatial effects are perceived by viewers. Therefore, if two dimensional menu screens are displayed during stereoscopic vision by viewers, the image becomes disorienting. Accordingly, there is a problem that stereoscopic viewing may be precluded because of the presence of the menu screens, regardless of the fact that the stereoscopic image is being displayed.
Japanese Unexamined Patent Publication No. 8 (1996)-249493 discloses a technique to be employed in compound lens cameras in order to solve this problem. In this technique, text and symbols are overlapped on each of two images which are used for stereoscopic viewing such that there is parallax therebetween. Thereby, the text and symbols are displayed three dimensionally in addition to the images, which are displayed three dimensionally. If this technique is applied, disorientation during stereoscopic viewing can be prevented, because the text and symbols are also displayed three dimensionally.
When three dimensional display is performed, the spatial effect during stereoscopic viewing differs according to the distance from subjects, which are included in images, to imaging sections. Specifically, spatial effects are perceived strongly in cases that subjects are at positions close to imaging sections during photography, because the amount of parallax is great. Conversely, spatial effects are perceived weakly in cases that subjects are at positions far from imaging sections during photography, because the amount of parallax is small. In the technique disclosed in Japanese Unexamined Patent Publication No. 8 (1996)-249493, text and symbols having a preset amount of parallax therebetween are overlapped on stereoscopic images. Therefore, the text and symbols can only express a constant spatial effect. Therefore, in cases that the amounts of parallax of subjects included in images differ from the amount of parallax of the text and symbols, the display of text and symbols becomes disorienting.